Starting off from noneuclidean geometries, apart from the method of Einstein's equations, this book derives and describes the phenomena of gravitation and diffraction. A historical account is presented, exposing the missing link in Einstein's construction of the theory of general relativity: the uniformly rotating disc, together with his failure to realize, that the Beltrami metric of hyperbolic geometry with constant curvature describes exactly the uniform acceleration observed. This book also explores these questions: Introduction Which Geometry? A Brief History of Light, Electromagnetism and Gravity Electromagnetic Radiation The Origins of Mass Thermodynamics of Relativity General Relativity in a Non-Euclidean Geometrical Setting Relativity of Hyperbolic Space Nonequivalence of Gravitation and Acceleration Aberration and Radiation Pressure in the Klein and Poincare Models The Inertia of Polarization Introduction to inverse semigroups; elementary properties of inverse semigroups; Ehresmann's maximum enlargement theorem; presentations of inverse monoids; inverse semigroups and formal languages; the type II theorem; complements

Includes bibliographical references (p. 373-403) and index